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02/25/2007

How to Conserve Water Efficiently-BECKER

The sharp rise in world population and income during the past five decades has stimulated greatly increased demand for clean water, and concern about whether the supply of water would be adequate to meet these needs. Demand for usable water in the future will surely continue to grow at a significant pace unless steps are taken to reduce demand, while the supply of water could grow more slowly, especially if global warming reduced rainfall and increased evaporation of water. The best way to bring demand into balance with supply is to introduce much more sensible pricing of water consumption than is common in most countries.
Many discussions of water conservation create the impression that households are large and inefficient users of clean water for drinking, eating, bathing, and toilet flushing. That is a myth. About 40 per cent of all the freshwater use in the United States is for irrigating land for agriculture, another 40 percent is used to produce power, and only 8 percent is used for domestic use; these percentages are similar in other countries. Moreover, about a third of all the water used by households in rich countries goes to water lawns and for other out door purposes, so probably no more than about 5 per cent of the total demand for water is for personal use.
Water used is usually a poor measure of the net amount of water consumed since much water is returned either immediately, or after evaporation and condensation, to the source pool, where it can be used again. Thermoelectric plants use a lot of water for cooling purposes, but typically have a very high reutilization rate (about 98 percent). Household use is also efficient, with a reutilization rate of about 75 percent. As a result, neither power producers nor households are big net consumers of water. Irrigation of farmland absorbs much water since most irrigation systems have low reutilization rates. In California, the biggest water using state, irrigation systems have a reutilization rate of only about 40 percent.
Governments usually try to close the gap between the supply and demand of usable water by command and control policies that regulate water use, usually starting with households. Many local governments have introduced requirements for low flow toilet flushes, bans on lawn watering except during certain hours or days, requirements for more efficient household outdoor watering systems, and other water conserving regulations. None of these regulations do anything to economize on the water used by farmers and industry, the main demanders of water.
Water is wasted in many ways by all sectors, and regulations do nothing to affect the main source of wasteful use of water: the inefficient pricing of water. Most irrigation systems in the world price water through annual flat fees, and not through charges that rise with the water consumed. Often domestic water use is not priced at all, and when priced, flat fees are far more common than fees that depend on use. As with any other scarce good, water is wasted when the cost of using more is negligible.
The obvious solution is to implement fees that rise with the amount of water demanded. Such fees are especially important in the agricultural sector since farming is a heavy consumer of water. Consumption ideally would be defined as net use after reutilization is accounted for. With this measure, the fee per gallon of water used would be low to power plants since they recover almost all the water they use. Farmers would tend to pay a lot both because they typically use much water, and also because most agriculture irrigation systems do a poor job of recovering the water used.
Fees that rise with consumption would reduce the demand for water partly by cutting demand. For example, households would water their lawns less frequently, and sometimes would replace natural grass with artificial grass, or with rock gardens and trees, Farmers would cut their demand for water by switching away from crops that require much water, such as rice, toward crops that need less, such as wheat. They would also switch to more efficient irrigation systems, such as spraying and dripping rather than flooding (which is the cheapest), if the price of water took account of reutilization rates. With proper water pricing, California and other regions that need expensive irrigation system to grow rice and other water-intensive crops would switch to other crops, or to other uses of their land, so that water-intensive crops would become more concentrated in areas with abundant water supplies. More generally, with sensible water pricing in different countries, arid parts of the world would not grow food that absorbs much water, and would shift to other crops and activities that they would exchange for these foods.
Some opponents of effective metering of water demand claim that it would not reduce the use of water because of the mistaken belief that most of the water used goes to households for drinking and personal hygiene. The demand for water for personal use may not be very responsive to price, but households in developed countries use lots of water for lawns and swimming pools that would be sensitive to the price of water. Also public and private golf courses and some other recreational facilities require much water, and these uses too would respond to higher water costs. Clearly, the use of water in agriculture and industry would be sensitive to its price.
Effective water pricing is even more important to poor countries since they cannot afford expensive methods of increasing the supply of usable water, such as desalinization, and since a large fraction of their water is used in agriculture with inefficient irrigation systems. Yet most poor countries make little effort to price water sensibly.
Implementation of significant fees is not easy politically since households and farmers believe they have a right to as much water as they can get. In particular, farmers in richer countries are well organized politically, and often resist efforts to raise the cost of water they use to irrigate their land. Perhaps their opposition could be weakened if they received generous reductions in their water fees when they introduce irrigation systems with high reutilization rates.

Comments

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it's hard to quarrel with this analysis, though I do wonder if ways of measuring re-utilization are readily available.

I would add that besides leading to waste of water the flat fee system probably results in inefficient allocation of agricultural land, since some land would be put to different use if water were priced sensibly.

One question, though. Northern Idaho. Water utilization is a function of well depth. Dry land farming is the norm. The water table has dropped, according to my uncle, eight feet. Housing starts are up.

Since so much of water usage is based on individual wells, I'm curious how metering would work. Would it be politically possible? Farmers know they're on a collision course with residential use, but are you willing to impose an external cost on residential users to indirectly subsidize farm use?

There is way to much case law to cite here. But water rights in the West are among the most significant court decisions in history. Especially their reliance on Interstate Commerce cases.

I see that Mr. Yomtov has the same type of concern. Although Mr. Yomtov doesn't mention the correct view that we should always consider "ambient esoteric considerations" when reviewing our model.

If only it were easy to introduce sensible pricing in irrigated agriculture!

People have tried and tried to introduce it, but in many cases it simply seems impossible. There are a lot of reasons for this: many irrigation systems in the developing world cover huge area's and thousands of farmers served by long canals in which controlling the flow of water is very hard. Supervision of the measuring devices (if they exist, they're very hard to make tamper-proof) would pose a great administrative burden on overstretched irrigation agencies.

I'm sure there are more reasons (and far better ones) one could think of. A search in google scholar or a scientific database on the word "volumetric pricing" and "irrigation" is sure to turn up some articles discussing the problems regarding water pricing in irrigation.

The basic estimating number for sizing water supply systems for human consumption is approx. 25 gpd per capita here in the U.S.. It may be that a price increase may very well drive down consumption somewhat, but I don't think it will. As was pointed out, the large consumers are industry and agriculture. For industry, they were historically located near large water resources in order to reduce the cost of this utility by having a large supply at hand, but not today. Large amounts of industry are now being located in either arid or semi-arid regions which places a tremendous burden on this natural resource in these areas. Cost increases may very well drive these industries out in search of more plentiful and less expensive water resources. Like returning to the rust belt. Agriculture being the other large user has also got problems with cost increases for water usage. It will only drive up the cost of food, a rather hard political sell.

As for the technical side of monitoring flow, that's simple, there are many types of flow meters available for either open channel or closed conduit flow that are accurate and highly reliable. Most American farms already utilize them along with various control valves to control irrigation of the fields. It doesn't do the crops any good to over water or under water. The objective is to achieve maximum crop yield per acre. That comes through the use of fertilizers, herbicides, pesticides, improved seed strains, and irrigation. The modern farm is a marvel of hi-tech. It just aint 40 acres and mule anymore. Like Faust modern man has made his bargain with the Devil and there is no turning back. The question becomes how much can we expand until we hit the wall?

I'd agree with nearly all of Posner's suggestions on this one. Whether "Libertarian" or other it attempts to get incentives lined up where they'll do the most good.

I remember CA used to have it backwards, in that agricultural water allotments were on a kind of "use it or lose it basis" and as water rights had economic value in themselves even if a farmer's current crops didn't need all of the allocation there was a strong incentive to use it up anyway. Anyone know if this has been fixed?

There's another reason to incent using "just enough" on farmlands as each round of irrigation adds mineral salts to the fields and is the reason much of the lands of the mid-east where irrigation was "invented" are no longer fertile today. The same is happening to much of our farmland and there are already efforts to find "salt-tolerant" crops in some areas.

It's interesting to consider the current subsidy driven mania for burning food in the tanks of our fleet of gas hogs in light of any potential global warming droughts.

I'm a bit puzzled about power generation consuming "40%". Is this lost from steam turbines or cooling nukies? I'd think there'd be condensers and waste heat scavengers on those today?

I live in Anchorage and both Alaska and Canada are energetically trying to get "Big Oil" on the stick to, finally! build the gas line that would supply 8-10% of US NG consumption from reserves known for the past 20 years. Perhaps someday, that 50" line and other oil lines from northern Canada will be used to supply water to the L-48. Hmmmm, using bio-fuel energy to pump water to grow bio-fuels?

Government made-up prices and fees are meaningless; they can never mirror the actual conditions of reality, the relative scarcity of the good in question.
Since the government doesn't depend on the revenue of its water provision to keep its operation, it will most certainly not do it in an efficient way, nor will it charge sensible prices.

Similar things happen to firms who are funded by the government or which hold monopoly power conferred on them by the government.

The obvious and only solution to the problem of water scarcity is the free unregulated market.

Water becoming too scarce? Prices would rise accordingly, and this of course would impel people to find new water sources and new ways to re-utilize and save water. No mystery, no magic; just people engaging in voluntary transactions to solve their problems and fulfil their needs.

Dear Becker-Posner,
this is the first time ive visited ur blog and have found it really interesting on the first glance. Talking about tinkering the demand mechanics of water.. it might apply only to the developed nations with a stable agriculural sector .. that accounts to about 10 % of the world population. Supply side mechanics of water management has to be applied to the underdeveloped nations and develloping countries.
The reason is that they rely on low technology, and labour intensive agricultural practices.
In most of the cases, they rely upon the monsoons.(ie 65% of the world population(ie Bangladesh,China and india).
Increasing the supply shall be a more sustainable approach as the approach involves an environmentally sensitive process. Afforestation, Rainwater harvesting and using Ground water while maintaining the aquifers.
Any household (of four persons) here India can become eternally SELF-Sufficient through rainwater harvesting and groung water useage (provided it falls in the + 1000mm rainfall belt). (www.rainwaterclub.org)
So its better we get back to the green way of living rather than.. using artifical Lawns as you have suggested).
Sustainable ideas are The Right ideas!

Dear Becker-Posner,
this is the first time ive visited ur blog and have found it really interesting on the first glance. Talking about tinkering the demand mechanics of water.. it might apply only to the developed nations with a stable agriculural sector .. that accounts to about 10 % of the world population. Supply side mechanics of water management has to be applied to the underdeveloped nations and develloping countries.
The reason is that they rely on low technology, and labour intensive agricultural practices.
In most of the cases, they rely upon the monsoons.(ie 65% of the world population(ie Bangladesh,China and india).
Increasing the supply shall be a more sustainable approach as the approach involves an environmentally sensitive process. Afforestation, Rainwater harvesting and using Ground water while maintaining the aquifers.
Any household (of four persons) here India can become eternally SELF-Sufficient through rainwater harvesting and groung water useage (provided it falls in the + 1000mm rainfall belt). (www.rainwaterclub.org)
So its better we get back to the green way of living rather than.. using artifical Lawns as you have suggested).
Sustainable ideas are The Right ideas!

Oregon guy's comments, )as well as Joel's and Ben's) has me wondering if our over-zealous "free market" advocates are familiar with the classic "Tragedy of the Commons" problem? The example is that of each family putting out to common pasture their goats, cows or sheep. Soon the commons are over-grazed and the livestock is scrawny and weak. But! it's a poor area and it's better for each family to have a scrawny goat than no goat at all. Meanwhile the commons is turning to dust.

Oregon points out the dropping of the water table in his area, it's also the case in the huge Oglalla aquifer that provides much of the well water of the mid-west. Would companies granted private rights to the water be likely to cut current production to ensure a continued supply?

Or, would they chase it down (as is being done today) for current "stock performance) with the spoils going to he who has the most drill pipe? To make matters worse, I suppose, both honest folk and profiteers could claim the draw down to be due to a temporary drought and that "another 20 feet" is "no biggie?"

VT Architect: Generally I agree as "real" lawns have a cooling effect in hot summers, provide some minimal "habitat" and help provide an area of water retention for roof runoff etc. Some places, parts of New Mexico come to mind have only token amounts of turf and leave most of the subdivision surroundings in its natural desert condition. Astroturf would be idiotic and would likely get sanded in by the winds as well.

The US may be moving, or has moved? well beyond "sustainable" by building in areas that no one would chose but for air conditioning and piping water long distances. Some of this is due to corporations chasing short term gains of the "wage race to the bottom" to low wage/low services states similar to OK, TN and others........ with almost NO concern for building "green" or conserving energy. Even solar panels are typically disallowed by subdivision covenants.

Wonder what will be heating and cooling these "praire mansions" fifty years from now?

Jack, Your ""tragedy of the commons" scenario deals with the problem of "carrying capacity" all too acute in arid and semi-arid regions. That was one of the underlying rationals of the development of the Colorado Doctrine which is what Judge Posner was discussing in terms of apportionment, allocation and allotment in Western Water Rights Law. As for your "prairie mansions", there are still a lot of ghost towns out here sitting as stark examples of what happens when the carrying capacity is exceeded and the tragedy of the commons occurs or the supporting industrial/mining base collapses.

As for "building green", my place still operates on the cistern that was installed over 150 years ago. The only problem is, when the rains disappear and the cistern goes dry, but you learn to extend it by rationing and then using your apportionment and allocation and cheating the cattle of their water ration and the other "dudes" further down on the apportionment list.

NE Hat: Thanks. Here in AK I may have in common with you dealing with the myriad of commons issue of Alaska. I'm most familiar with the harvesting of our various fisheries that contribute 1/8th of America's protein production. You can imagine the issues of protecting the targeted species, by-catch of scarcer but higher priced fish, gear conflicts etc. Alaska's statehood has its roots in SEA canning interests raping the resource with fish traps and leaving fewer crumbs for Alaskan fishermen than say Walmart leaves in the towns it pumps out.

As for water about every second stream and lake is host to salmon or some other specie of fish, while in half the state there's the issue of logging to the stream banks, cutting steep roads with the silt running off to ruin salmon spawning gravel beds, and the question of what sort of water quality should copper, tin or gold mining operations return to the pristine streams and rivers.

"Our" largely state-owned oil reserves pose another massive interface between public and private with 10's of millions at stake..... DAILY!

As I suppose is the case with western water one thing it never is, is easy or clear cut! And it's never final.

Ha! I lived on a Maine island with a well and cistern in my youth. Nothing like packing water by hand to keep consumption down! In dealing with OK and its fields of "prairie mansions" it's interesting to note the old bungalows with shaded porches by comparison to new construction so dependent on A/C they don't bother to even shade south facing windows and most subdivisions have covenants against solar panels. I fear our private home building industry and buyers who think in very short terms (and lack of public oversight) are building a mess that will test future carrying capacity of those areas.

One thing I heard from an Idaho congressman once was "You can mess with my wife, but don't touch my water."! Interesting post. I think that water would be better served if there was a futures market for water. You because in farming there should be a cycle of demand for water, more water used at earlier stages of the growing season. If market prices were allowed to fluctuate, and a futures market put in place, you would rationalize prices on water. Once the price got too high, usage would go down.

Once "prices got too high" would the "private" supplier be the beneficiary of the payment of high prices?? BTW..... Since oil prices have risen so dramatically US consumers have paid an extra Trillion dollars, and consumption has not changed much. Kind of an issue of elasticity of demand I suppose? Otherwise known as being jacked between a rock and a hard place with precious few options beyond grinning and bearing it. Would there be reason to expect better results from water unless water prices SOARED and stayed that way for a long time?

Good evening. If we fall, we don't need self-recrimination or blame or anger - we need a reawakening of our intention and a willingness to recommit, to be whole-hearted once again.
I am from Niger and learning to write in English, give true I wrote the following sentence: "Nec litre capacity small refrigerator as new,white goods, gumtree classifieds."